Funeral pyres expire long before they should

[PALU]

Again I've tried to make a funeral pyre for a robber posse victim (an old man, as all the adventurers are unavailable now but possibly in the future). A log, 5 slender trunks, and some branches, which were reported to burn into the small hours. I left the area to pick up my cow of burden and returned a couple of hours later, to find (as I now expect) that the fire is out and the funeral subject isn't particularly burnt.